Buckling behaviour of imperfect axially compressed cylinder with an axial crack

Abstract

This paper studies the buckling behaviour of cylindrical shell structures with an axial
crack subjected to axial compression. This work is both experimental and theoretical. The results of the test on four laboratory scale mild steel cylinders and the associated theoretical estimation of the buckling loads for a cylinder with no cracks are provided. The geometry parameters of the cylinder were assumed as follows: the radius-to-thickness ratio (R/t) was taken as 100, while the axial length-to-thickness ratio L/R, was 2.2. The nominal thickness of the specimen was 0.5 mm. Cylinders had an axial crack introduced to a fraction of the cylinder’s axial length. The magnitude of the crack length-to-cylinder axial length varies between 0 and 0.15. All four cylinders were subjected to axial compression using an instron universal testing machine. The experimental results reveal that the load carrying capacity of the cylindrical shells is strongly dependent on the crack length, i.e., increasing the crack length leads to a decrease in the buckling load of the cylindrical shells. As an example, the cylinder with an axial crack extending by 15% of its axial length will lead to an approximate reduction of 31% in the load carrying capacity of the shell.